High Altitude experience with Dreamstation APAP.

[NorthernGuy]

So, I got back from a vacation in the mountains. I started in Denver (5200 feet) and moved up stepwise over a week to ~9000 feet). These are the nightime sleeping altitudes - I was hiking at 10-12k feet during the day. After about 5 days, I didn't know notice the altitude, but my AHI's were elevated.

My AHI (clear apnea and hypopneas went up - obstructive stayed constant) and especially "periodic breathing" both went up multiple-fold (5-7x) on the first night at a higher altitude and then slowly decreased until moving up in altitude again. I would have loved to stay and continue the experiment longer to see where my AHI would level off at high altitude (vs. near sealevel where I live), but my vacation ended.

Upon returning, by the second night, I was exactly back to "normal".

I was definitely above the altitude rating of the DreamStation and didn't change any settings. The machine ran OK, with no errors or notices (other than surprisingly high AHI and periodic breathing). What does the machine actually do to compensate for altitude? I thought the machine only measured the difference in pressure between inside of the mask and outside of the mask (not absolute pressure above sea level). The blower probably has to work harder to pressurize the thinner air, but not sure what would be different at intermediate pressures?

Any high altitude living people comment if they achieve an AHI <=5 and what their periodic breathing percentage number is???

[richb]

There is a strong correlation between "high altitude sickness" and periodic breathing. Not that you experienced high altitude sickness, but that your body was experiencing some of the effects of hyperventilation. Your changes in breathing due to altitude removes "washes out" CO2 and tricks your brain into thinking that you have done enough breathing. That shows up as an increase in CA events and periodic breathing waveforms when on CPAP. I would guess that you would adjust to the altitude (increased red blood cell count) over time and have less of these events if you lived at altitude for a long period of time. There might be short term tweaks that might help such as reducing pressure relief and or tightening the differential between IPAP and EPAP pressures. Your experience with altitude has been studied as part of the investigation into Central Apnea and Periodic Breathing not associated with Chronic Heart Failure.

Rich

[NorthernGuy]

Thanks for the reply. I had no symptoms of Acute Mountain Sickness (AMS) and my hiking performance was surprisingly good for only being at altitude for about a week. Summitted some peaks at ~13,500 feet in Estes Park with little problem. Had a ton of fluid loss (but maybe that was from drinking so much water as suggested in all of the literature).

Wondering if there are any XPAP users living at 7,500 ft+ and want to give us their experience after being acclimatized. Do CA and periodic breathing events ever go down? Below 5? What machines they use and if they made any special adjustments.

BTW, fuel injected car engines perform a whole lot better at 12,000 feet than the old carburetor versions that I drove last time I was out there many (many) years ago.

[richb]

Here is a thread on this board that discusses high altitude and central apnea. http://www.apneaboard.com/forums/Thread-...ral-Apneas

Rich

[justMongo]

BTW, fuel injected car engines perform a whole lot better at 12,000 feet than the old carburetor versions that I drove last time I was out there many (many) years ago.

Carbureted cars ran richer and richer with increased altitude. People who lived at high altitudes generally had leaner main jets.

Fuel injected cars have absolute manifold pressure sensors, mass airflow sensors, and oxygen sensors in the exhaust flow. They are better able to self adjust to altitude.

However, both injected and carbureted cars produce less torque and horsepower at altitude.

That's why piston driven aircraft are turbocharged for performance at altitude -- to pack more air into the cylinders.

[0rangebear]

Wondering if there are any XPAP users living at 7,500 ft+ and want to give us their experience after being acclimatized.

Estes park is great its is 50 miles form my place.

We like to spent a day making the loop through Estes and the rocky mountain nation Park. The high point is 11,307 @ Berthoud Pass. My 2015 Honda doesn't run much different up there but my 93 Jeep sure does.

I live at 5,420 ft. but I work @ 7,220 ft. I frequently spend time above 10,00 feet but rarely do I go above 12,500. It is common for anyone traveling above 5000 ft. to see an increase in centrals.

I have been told that my machine compensates, which appears to be true because I do not see a significant change in nights above 10,000 ft.

I did have mostly CA's and Hyp when I started therapy. I rarely see a CA now maybe one a month. Mostly Hyp

When people move to the Rockies it often takes them several weeks to acclimate to the thinner Air. Many of those people end up seeking medical help at some point because they feel like they can't breath, The EMT's typically them with CPAP.

If you watch the Bronco sidelines when they are playing at home. you'll see a lot of players from low elevations sucking oxygen during the games

Go Broncos, best home field advantage

[NorthernGuy]

When people move to the Rockies it often takes them several weeks to acclimate to the thinner Air. Many of those people end up seeking medical help at some point because they feel like they can't breath, The EMT's typically them with CPAP.

If you watch the Bronco sidelines when they are playing at home. you'll see a lot of players form low elevations sucking oxygen during the games

Go Broncos, best home field advantage

I guess it takes several weeks to fully acclimatize. Unfortunately I wasn't there long enough. Does make for a good home field advantage. :-)
Thanks for sharing your experiences.